Android开发欢迎页点击跳过倒计时进入主页

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/a">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:id="@+id/tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_marginRight="20dp"
            android:layout_marginTop="10dp"
            android:textSize="20sp" />
    </RelativeLayout>
</LinearLayout>

package com.cwj.test;
import android.content.Intent;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.WindowManager;
import android.widget.TextView;
import java.util.Timer;
import java.util.TimerTask;
public class SpActivity extends AppCompatActivity implements View.OnClickListener {
    private int recLen = 5;//跳过倒计时提示5秒
    private TextView tv;
    Timer timer = new Timer();
    private Handler handler;
    private Runnable runnable;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //定义全屏参数
        int flag= WindowManager.LayoutParams.FLAG_FULLSCREEN;
        //设置当前窗体为全屏显示
        getWindow().setFlags(flag, flag);
        setContentView(R.layout.activity_sp);
        initView();
        timer.schedule(task, 1000, 1000);//等待时间一秒，停顿时间一秒
        /**
         * 正常情况下不点击跳过
         */
        handler = new Handler();
        handler.postDelayed(runnable = new Runnable() {
            @Override
            public void run() {
                //从闪屏界面跳转到首界面
                Intent intent = new Intent(SpActivity.this, MainActivity.class);
                startActivity(intent);
                finish();
            }
        }, 5000);//延迟5S后发送handler信息
    }
    private void initView() {
        tv = findViewById(R.id.tv);//跳过
        tv.setOnClickListener(this);//跳过监听
    }
    TimerTask task = new TimerTask() {
        @Override
        public void run() {
            runOnUiThread(new Runnable() { // UI thread
                @Override
                public void run() {
                    recLen--;
                    tv.setText("跳过 " + recLen);
                    if (recLen < 0) {
                        timer.cancel();
                        tv.setVisibility(View.GONE);//倒计时到0隐藏字体
                    }
                }
            });
        }
    };
    /**
     * 点击跳过
     */
    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.tv:
                //从闪屏界面跳转到首界面
                Intent intent = new Intent(SpActivity.this, MainActivity.class);
                startActivity(intent);
                finish();
                if (runnable != null) {
                    handler.removeCallbacks(runnable);
                }
                break;
            default:
                break;
        }
    }
}

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
</style>

public class WelcomeActivity extends Activity{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.welcome);
        /**
         * 延迟3秒进入主界面
         */
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent intent=new Intent(WelcomeActivity.this,LoginActivity.class);
                startActivity(intent);
                WelcomeActivity.this.finish();
            }
        },1000*3);
    }
}

public class LoginActivity extends Activity{
    SharedPreferences sprfMain;
    SharedPreferences.Editor editorMain;
    Button login;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //在加载布局文件前判断是否登陆过
        sprfMain= PreferenceManager.getDefaultSharedPreferences(this);
        editorMain=sprfMain.edit();
        //.getBoolean("main",false)；当找不到"main"所对应的键值是默认返回false
        if(sprfMain.getBoolean("main",false)){
            Intent intent=new Intent(LoginActivity.this,MainActivity.class);
            startActivity(intent);
            LoginActivity.this.finish();
        }
        setContentView(R.layout.login);
        login= (Button) findViewById(R.id.login);
        //这里只是简单用按键模拟登录功能
        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(LoginActivity.this,MainActivity.class);
                editorMain.putBoolean("main",true);
                editorMain.commit();
                startActivity(intent);
                LoginActivity.this.finish();
            }
        });
    }
}

public class MainActivity extends AppCompatActivity {
    SharedPreferences sprfMain;
    SharedPreferences.Editor editorMain;
    Button exit;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        exit= (Button) findViewById(R.id.exit);
        exit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            //点击注销按键后调用LoginActivity提供的resetSprfMain()方法执行editorMain.putBoolean("main",false);，即将"main"对应的值修改为false
                resetSprfMain();
                Intent intent=new Intent(MainActivity.this,WelcomeActivity.class);
                startActivity(intent);
                MainActivity.this.finish();
            }
        });
    }
    public void resetSprfMain(){
        sprfMain= PreferenceManager.getDefaultSharedPreferences(this);
        editorMain=sprfMain.edit();
        editorMain.putBoolean("main",false);
        editorMain.commit();
    }
}